Maca coffee is ordinary coffee with powdered maca root stirred in, so it still has the coffee’s caffeine. Maca’s health benefits are unproven: the few small trials were mixed. Side effects are uncommon and mild, mostly stomach upset and headache. Ask a doctor first if you are pregnant, nursing, on medication, or have a thyroid or hormone condition.
Medical disclaimer: this page is general information about a food and a supplement ingredient. It is not medical advice, it is not a diagnosis, and it is not a treatment plan. Maca is a dietary supplement ingredient, not a medicine. Talk to a doctor or pharmacist before adding any supplement, especially if you are pregnant or nursing, take prescription medication, or have a thyroid, hormonal or cardiac condition.
Table of Contents
What maca is
Maca (Lepidium meyenii) is a root vegetable in the mustard family, grown high in the Peruvian Andes. LiverTox describes it as “a food and traditional herbal medicine derived from the roots of a perennial plant (Lepidium meyenii) cultivated at high altitudes in the Andes mountains,” notes that its principal components are carbohydrates and protein, and that it is “an excellent source of essential amino acids, iron and calcium.” The root is dried and milled to a powder; maca coffee is that powder stirred into brewed coffee, or blended with coffee before brewing.
We have not tasted maca coffee, so we do not describe how it tastes.
Does maca have proven health benefits?
No. LiverTox, the NIH’s database on supplements, drugs and liver injury, says of the effects maca is promoted for: “None of these effects have been proven in prospective, rigorously controlled trials in humans” (LiverTox, NIDDK/NIH). The research is thin rather than negative: a few small randomised trials report effects, and a 2018 review of maca’s reproductive-health claims concluded that “the health claims of maca cannot be fully supported from a scientific standpoint and more research is needed” (Beharry and Heinrich, Journal of Ethnopharmacology 2018). The trials are small and short, and they tested different products and doses:
| Trial | Who | Dose and length | What it reported |
|---|---|---|---|
| Meissner et al., 2006 | 34 early-postmenopausal women | 2 g a day; four-month crossover with placebo | Raised estradiol and lowered FSH and T3, among other hormone changes; eased menopausal symptoms |
| Stojanovska et al., 2015 | 29 postmenopausal women in Hong Kong | 3.3 g a day for 6 weeks; crossover with placebo | No difference from placebo in estradiol, FSH or TSH; diastolic blood pressure and depression scores fell after maca (the abstract does not compare these two with placebo) |
| Gonzales-Arimborgo et al., 2016 | 175 adults in Peru | 3 g of red or black maca extract a day for 12 weeks | Better mood, energy and health status than placebo; no serious adverse effects |
| Shin et al., 2023 | 80 men with symptoms of late-onset hypogonadism | “1,000 mg of Maca or placebo, two pills at a time, three times per day for 12 weeks” | Ageing-male symptom, erectile-function and prostate-symptom scores improved more than with placebo |
For sexual function, a 2010 systematic review of randomised trials searched 17 databases and found four trials that qualified. Its conclusion, verbatim:
“The results of our systematic review provide limited evidence for the effectiveness of maca in improving sexual function. However, the total number of trials, the total sample size, and the average methodological quality of the primary studies were too limited to draw firm conclusions. More rigorous studies are warranted.”
— Shin et al., Maca (L. meyenii) for improving sexual function: a systematic review, BMC Complementary and Alternative Medicine, 2010 (PMC2928177)
“Limited evidence, too limited to draw firm conclusions” is not the same as “a natural aphrodisiac.” LiverTox lists the same gap for every other benefit maca is sold on (memory and learning, mood, energy, stamina, sperm count) and says studies in humans “have had conflicting results.” Animal studies exist; they are not evidence of an effect in people.
Can maca treat or prevent disease?
Not as a supplement. Saying a supplement reduces the risk of heart disease or cancer, or treats depression, is a disease claim. The FDA is explicit that this is territory only drugs may enter: a supplement label carrying a structure/function claim must state that the product “is not intended to ‘diagnose, treat, cure or prevent any disease,’ because only a drug can legally make such a claim” (FDA, Label Claims for Conventional Foods and Dietary Supplements). The NIH Office of Dietary Supplements puts the same point to consumers: “Dietary supplements are products intended to supplement the diet. They are not medicines and are not intended to treat, diagnose, mitigate, prevent, or cure diseases” (ODS, Dietary Supplements: What You Need to Know).
Side effects and who should be careful
On maca itself, LiverTox reports: “Side effects of maca are uncommon and mild, and mostly include gastrointestinal symptoms and headaches,” and that “In small clinical trials, maca extracts have been reported to be safe, well tolerated and with only minor, transient adverse effects.” It assigns maca a likelihood score of E — unlikely cause of clinically apparent liver injury — while noting that as a supplement, maca “has had limited use.” Reassuring, but from a small evidence base.
- Pregnancy and nursing. ODS advises: “Be cautious about taking dietary supplements, beyond a standard prenatal supplement, if you are pregnant or nursing,” and adds that “Many supplements have not been well tested for safety in children and in women who are pregnant or nursing.” That covers maca.
- Children. Same ODS guidance: be careful about giving supplements to a child unless their health care provider recommends it.
- Thyroid conditions. Whether maca affects the thyroid is unsettled. Maca is in the mustard family, and LiverTox records that it contains glucosinolates, but the small human trials that measured thyroid hormones do not settle it: T3 fell in one (Meissner et al., 2006) and TSH did not change in another (Stojanovska et al., 2015). Treat this as a reason to ask your doctor, not as an established effect.
- Hormone-sensitive conditions and hormone therapy. The same applies. Small trials disagree on whether maca changes hormone levels: one (Meissner et al., 2006, 34 women) reported changes in several hormone levels, and a later trial (Stojanovska et al., 2015, 29 women) found no change in estradiol, FSH or TSH. That is exactly the sort of uncertainty worth raising with the clinician managing your treatment.
- Product quality and other medicines. The 2018 review warns that the lack of rules for producing and marketing maca “poses a threat to both the safety of consumers and the sustainability of supply”. A 2021 study of maca grown near mining areas in Peru’s Junín province found mean cadmium (0.32 mg/kg) and lead (0.20 mg/kg) above FAO and WHO limits. The estimated daily intake of each metal was below its reference dose, but the authors also estimated a cancer risk from arsenic and cadmium above the tolerable limit for children and adults eating the local maca. They sampled maca from mining-affected districts, not retail products (Orellana Mendoza et al., Toxicology Reports 2021). A 2020 review of the psychiatric and neurological side effects of herbal sexual enhancers found little on maca beyond one case report of a manic-like episode, called its safety profile good, and named no maca-specific drug interaction (Brunetti et al., Pharmaceuticals 2020). If you take prescription medicines, ask your pharmacist before adding maca.
- The coffee half. Maca coffee is still coffee. The FDA has cited “400 milligrams a day — that’s about two to three 12-fluid-ounce cups of coffee — as an amount not generally associated with negative effects” for most healthy adults (FDA). If coffee already upsets your stomach, adding a supplement whose most common side effect is gastrointestinal is not an obvious win — see why coffee makes some people nauseous.
How much, and how to make it
There is no established dose, because there is no established use. LiverTox records that “The recommended daily dose varies widely (500 to 3000 mg daily), depending on the preparation used (capsules, tablets, liquid, root extract) and indications” — that is a description of what products on the market suggest, not a recommendation, and this page is not making one. Follow the dose on the product you actually bought, and start at the low end of it.
Preparation is trivial: brew coffee as you normally would, stir in maca powder until it disperses, taste, adjust. It dissolves better in hot liquid and better still if you whisk or blend it. That is the whole method.
What this page will not tell you
It will not tell you that maca coffee is a pre-workout, an antidepressant, a fertility treatment, a blood-pressure drug or a cancer preventive, because nobody has shown that it is any of those things. It is a root vegetable powder with a long history of food use, a small and mixed clinical literature, and a mild side-effect profile. If you like the taste and it agrees with you, that is a sufficient reason to drink it. It is also the only reason this page can honestly give.
Corrections to earlier versions of this page
- Unsourced health claims. An earlier version listed heart-disease, cancer, depression, fertility and blood-pressure benefits without a source. They have been removed; what the small trials found is set out above.
- “A natural aphrodisiac”. An earlier version called maca that. The systematic review above found the evidence too limited to draw firm conclusions.
- Thyroid and hormones. An earlier version stated as fact that maca contains goitrogens that interfere with thyroid function, and that it “can potentially affect hormone levels.” The small trials that measured these disagree, so the page now treats both as reasons to ask your doctor.
- Taste. An earlier version gave specific flavour descriptions, including a “subtle hint of butterscotch”. We have not tasted maca coffee, so they have been removed.
- Preparation. An earlier version spread the method over five numbered steps; it takes two sentences.
